we love perogies- and since i am usually too lazy or too busy to actually make them, Mrs. T's frozen ones work perfectly for us.
i usually cook them using the baking instructions. simply follow the directions on the package and enjoy!
if we're eating them with something else we usually boil them & eat them with butter. but if we're eating them alone, after baking them we eat them with sour cream (ketchup isn't bad either)